1. Field of the Invention
The present invention relates to a ventilation system for electrical wiring arrangements of electrical circuits.
In particular, the present invention relates to a ventilation system for electrical wiring arrangements of electrical circuits present in devices, apparatuses and/or sensors that can be installed in a motor vehicle, to which the following explanations will make explicit reference, without thereby restricting the general scope thereof.
2. Description of Related Art
As is known, some types of control devices, in particular some types of sensors typically used in motor vehicles, are provided with one or more electrical terminals for connecting the electrical circuit of the sensor and with an inner chamber hermetically closed relative to the outside environment, i.e. tightly sealed, said cavity being capable of accommodating therein one or more electrical wiring arrangements between the electrical terminals of the sensor and the associated electrical connection cables, which are capable of connecting said sensor to corresponding electronic devices installed in the vehicle, such as for example the central sensor control unit and/or the remote central electronic unit.
It is furthermore known that when said sensors are installed in the vehicle close to a heat source, the air present within the inner chamber is subject to considerable fluctuations in temperature, which bring about great expansions and contractions of volume within said inner chamber, so causing an “air pumping” effect, which promotes the formation of moisture in said inner chamber, with all the associated disadvantages.
With the aim of avoiding said disadvantages, a terminal of the above-mentioned sensors is normally connected to the remote central electronic unit by means of an electrical cable, hereinafter denoted “electrical ventilation cable”, which is capable both of effecting electrical connection of the sensor to the remote central electronic unit and of bringing the inner chamber of the sensor, and thus the associated electrical wiring arrangement, in direct communication with an environment under atmospheric pressure. In the present case, the electrical ventilation cable is made in such a manner as to permit a stream of air to pass between the two ends, a first end of which is wired to the electrical terminal present in the inner chamber of the sensor, while the second end is wired to the electrical terminal present within a chamber of the remote central electronic unit, which is typically in communication, via a valve, with the outside environment and is thus at atmospheric pressure.
Unfortunately, ventilating the inner chamber of the sensor is not feasible when the second end of the electrical ventilation cable is connected to a terminal (of any device) accommodated within a chamber that is hermetically sealed relative to the outside environment or to a terminal that is completely embedded in an insulating material. Such a situation arises, for example, when the wiring arrangement is produced between the sensor and central sensor control unit, the terminals of which are themselves completely embedded in an insulating material; in this case, the air present in the inner chamber of the sensor is not capable of expanding freely through the electrical ventilation cable, so giving rise to the same disadvantages described above, namely the possible formation of moisture in the inner chamber of the sensor.